title: Engineering of the alpha-amylase from Geobacillus stearothermophilus US100 for detergent incorporation.
abstract: AmyUS100DeltaIG is a variant of the most thermoactive and thermostable maltohexaose forming alpha-amylase produced by Geobacillus stearothermophilus sp.US100. This enzyme which was designed to improve the thermostability of the wild-type enzyme has acquired a very high resistance to chelator agents. According to modeling structural studies and with the aim of enhancing its resistance towards chemical oxidation, a mutant (AmyUS100DeltaIG/M197A) was created by substituting methionine 197 to alanine. The catalytic proprieties of the resulting mutant show alterations in the specific activity and the profile of starch hydrolysis. Interestingly, AmyUS100DeltaIG/M197A displayed the highest resistance to oxidation compared to the AmyUS100DeltaIG and to Termamyl300, the well-known commercial amylase used in detergent. Further, performance of the engineered alpha-amylase was estimated in the presence of commonly used detergent compounds and a wide range of commercial detergent (liquid and solid). These studies indicated a high compatibility and performance of AmyUS100DeltaIG/M197A, suggesting its potential application in detergent industry.
authors.affiliation: Centre de Biotechnologie de Sfax B.P. "K" 3038 Sfax, Tunisie.
authors.forename: Bassem
authors.initials: B
authors.lastname: Khemakhem
authors.forename: Mamdouh Ben
authors.initials: MB
authors.lastname: Ali
authors.forename: Nushin
authors.initials: N
authors.lastname: Aghajari
authors.forename: Michel
authors.initials: M
authors.lastname: Juy
authors.forename: Richard
authors.initials: R
authors.lastname: Haser
authors.forename: Samir
authors.initials: S
authors.lastname: Bejar
mesh_terms: D000409:Alanine / Q000737:chemistry / Q000235:genetics; D019943:Amino Acid Substitution; D001407:Bacillus / Q000201:enzymology*; D002384:Catalysis; D003902:Detergents / Q000737:chemistry*; D004795:Enzyme Stability / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D006358:Hot Temperature; D008715:Methionine / Q000737:chemistry / Q000235:genetics; D016296:Mutagenesis; D009844:Oligosaccharides / Q000096:biosynthesis; D010084:Oxidation-Reduction; D011487:Protein Conformation; D015202:Protein Engineering; D013329:Structure-Activity Relationship; D000516:alpha-Amylases / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*
chemical_list: D003902:Detergents; D009844:Oligosaccharides; C016549:maltohexaose; D008715:Methionine; D000516:alpha-Amylases; D000409:Alanine